Comparison of 532-nm GreenLight HPS laser with 980-nm diode laser vaporization of the prostate in treating patients with lower urinary tract symptom secondary to benign prostatic hyperplasia: a meta-analysis

The thermal effect of lasers in urology: a review article

Lasers as a technology have a leading role in the modern urological treatment armamentarium. In this article, the application of lasers in different areas of urology is described. The major uses are in urolithiasis, benign prostatic enlargement (BPE), and management of many urological malignancies and other benign pathologies. Lasers have become an established treatment modality in urolithiasis, an acceptable alternative with the least side effect profile in BPE patients, and a novel and promising therapy in many other fields of Urology.

Wound healing process in beagles after vaporization of the prostate with a novel 200W 450-nm laser

In comparison to other commercially used lasers, the coagulation layer of the novel 450-nm laser is thinner, and this coagulation layer's thickness is a key factor influencing wound healing. In this study, we investigated whether the novel 200W 450-nm laser system (BR6800, Blueray Medical Ltd., Shaanxi, China) is superior to classic transurethral resection of the prostate (TURP) for wound healing in beagles. Twenty-two 6-to 8-year-old male beagles were treated with TURP or blue laser vaporization of the prostate (BLVP). Prostate wounds were observed via cystoscopy at 3 h and at 1, 2, 3, and 5 weeks post-operation (two beagles per group). Additionally, two elderly beagles without surgery served as normal controls. After cystoscopy examination, prostate samples were collected and fixed for hematoxylin and eosin (H&E) and immunofluorescence staining to observe wound healing progression under microscopy. The urethras of prostates under cystoscopy in BLVP groups were healed three weeks after surgery, while in the TURP group, they were healed five weeks after surgery. H&E staining confirmed that the coagulation necrosis layer in the TURP group was thicker than that in the BLVP group and it took longer to remove coagulation necrosis after surgery. Macrophage polarity transformation was also earlier in the BLVP group. The new 200W 450-nm laser was superior to TURP for wound healing. The thinner coagulation layer of the 450-nm laser was the primary reason for this process.

Network meta-analysis of the treatment safety and efficacy of different energy systems in prostate vaporization

Many clinical trials and meta-analyses have examined vaporization with different energy instruments has been recognized by the American Urological Association (AUA) and the European Association of Urology (EAU) as a promising treatment for benign prostate hyperplasia. However, there is still a lack of evidence for a network comparison between different vaporization devices. The PubMed, Embase, Cochrane and Web of Science databases were searched to identify randomized controlled trials (RCTs) of different energy systems for prostate vaporization. Pairwise and network meta-analyses (NMA) were performed to analyze the outcome regarding surgery time, complications, short-term maximum urine flow rate (Qmax), and long-term Qmax. The Stata software was used for paired meta-analysis. A Bayesian NMA model with ADDIS software was applied to achieve the indirect comparison of different energy systems. Node-splitting analysis and inconsistency factors were used to test inconsistency for closed-loop indirect comparison. Fifteen studies were included in this study, involving three types of energy systems used in prostate vaporization: diode laser (wavelength: 980 nm, power: 200-300 W, mode: continuous), green-light laser (wavelength: 532 nm, power: 80-180 W, mode: continuous), and bipolar plasma vaporization (bipolar electrode, power: 270-280 W, mode: pulsed). In the conventional paired meta-analysis, significantly better short-term efficacy was found in green light laser vaporization, while no significant difference was detected in other parameters. According to the results of the NMA, a greenlight laser is recommended for prostate vaporization rather than the other two systems. When considering operation time, overall complications, short-term Qmax, and long-term Qmax, there were no significant differences among green-light laser vaporization, diode laser vaporization, and bipolar vaporization in BPH treatment. However, according to the probability ranking and benefit-risk analysis results, the green-light laser might be the best energy system for prostate vaporization in BPH treatment.

A prospective, single-center, randomized clinical trial to evaluate the efficacy of three types of laser vaporization surgeries using a 180-W GreenLight XPS laser, a 300-W diode laser, and a 200-W thulium laser for the treatment of benign prostatic hyperplasia

OBJECTIVES

This study aimed to compare the safety and efficacy of three different laser prostate vaporization surgeries, which were photoselective vaporization of the prostate (PVP), diode laser vaporization (DVP), and thulium laser vaporization (ThuVAP), for the treatment of benign prostatic hyperplasia (BPH) in a randomized clinical trial.

METHODS

A total of 71 consecutive patients with BPH were included; 23 patients were treated with PVP, 23 with DVP, and 25 with ThuVAP. Patients were evaluated with disease-related symptomatic questionnaires, Quality of Life (QOL) Index, and maximum urinary flow rate (Q_max ) for 12 months. Patients were monitored to record operation/vaporization time, 24-hour hemoglobin/sodium drop, length of catheterization/hospitalization, and perioperative/postoperative complications.

RESULTS

In all three groups, patients showed significant and comparable improvements in symptom scores, QOL Index, and Q_max during the 12-month follow-up period. The mean operation/vaporization time was equivalent across all three groups at 69/23 (PVP), 81/34 (DVP), and 76/32 minutes (ThuVAP), while the applied laser energy was lower for PVP at 157 kJ compared to the other two techniques (DVP at 358 kJ, ThuVAP at 240 kJ). The mean vaporization rates per unit energy were significantly different between the three groups (PVP 0.16, DVP 0.09, and ThuVAP 0.09 mL/kJ). There were no significant differences in the main safety profiles between the three groups.

CONCLUSIONS

Our study demonstrated that these three types of laser surgeries are similar in terms of complications and outcomes, with excellent hemostasis and high patient satisfaction. It was suggested that sufficient tissue vaporization could be achieved using less energy through PVP surgery.

Thulium fiber laser in urology: physics made simple

PURPOSE OF REVIEW

In this narrative review, we will focus on a novel thulium fiber laser's physical properties in terms of its clinical applicability.

RECENT FINDINGS

TFL has successfully moved forward from the preclinical trials into clinical practice and now is being widely used in clinics around the world. The available data suggest that the device effectively operates in soft tissues - benign prostate hyperplasia (BPH) and bladder tumors, as well as in lithotripsy. Also, the first promising results were obtained from laparoscopic surgery showing its possible applicability in the management of renal cell carcinoma. The constructional changes in fiber laser's design, lead to alteration of laser-tissue interactions, which resulted in clinical advantages of the device. Yet, the exact mechanism often is considered complex for understanding. With this work, we are aiming to build a bridge between biophysics and clinical practice and give a simple explanation of how the devices is working and why the knowledge of it is important for a clinician.

SUMMARY

The more effective wavelength (closer to the water absorption peak), favorable beam profile, different modes of action allowing to decrease carbonization on one hand and retropulsion on the other, all this makes TFL an evolution in urologic surgery. Further trials investigating on the possible pros and cons of the device are awaited.